Virtual reality is a computer technology that replicates an environment, real or imagined, and simulates a user's physical presence to allow for user interaction. Virtual realities artificially create sensory experiences, which can include sight, touch, hearing, and smell, and are displayed either on a computer screen or with a special virtual reality headset (also called a head-mounted display).
Augmented reality displays a view of a physical, real-world environment whose elements are supplemented by computer-generated sensory input such as sound, video, graphics, or GPS data. Thus, the technology functions by enhancing one's current perception of reality. Augmentation is conventionally done in real-time and in semantic context with environmental elements, such as sports scores on TV during a match. With the help of advanced augmented reality technology (e.g. adding computer vision and object recognition), information about the surrounding world of the user can be overlaid on the world and become interactive and digitally manipulable.